1986 5.0 Bronco Fuel Pump Q.
The wiring shorted out due to the "custom wiring" job done by the previous owners. There are 5 red wires coming into the cab (3 go to the computer harness, 1 to the relay, and 1 more to a connector that isn't hooked up to anything), and they were stripped and all crimped/welded together with what appears to have been a hot pair of pliers. The wire to the relay shorted and smoked, and the snapped in 2. I rewired the wires seperately and put a new wire to the relay. The factory relay and the new relay both click when I turn the ignition on, but the pumps didn't turn on. After hours of trying other things, I was running a wire directly from the battery to the fuel pump wires to see if they would even turn on or not. The High pressure pump turns on just fine, but the in-tank pump makes a really quiet noise like it is dying, and the truck still didn't turn on after both pumps appeared to be on. Also, when checking the wires with a test light and ignition on. None of the 5 red wires had power, the yellow wire coming off of the tank for the fuel gauge made the test light flash, and of the grounds had no power (at least something is working right!)
What sound exactly does the in-tank pump make when it turns on? The high pressure pump makes a louder, whining sound. I am just trying to figure out if the pump is bad before I try and siphon out the full tank of gas (truck ran for about 30 seconds after completely filling up) to drop the tank. I have a repair manual and it doesn't tell a whole lot about it.
I'd really appreciate any help I can get!!!
Last edited by roushstage2; 03-04-2008 at 01:42 AM.